Leadbelly sang of them, Malcolm X wrote about being one. Light-skinned African-Americans with high yellow or red bone complexions have always been targets of scorn among darker blacks because the yellowmen were presumed to be favored by whites  and often flaunted the fact they were. This bitter blood rift is the focus of Dael Orlandersmiths must-see play, Yellowman, a harrowing fable about American prejudice that has been running at the Fountain Theater to full houses since winter.

The contemporary story, set among Gullah descendants of South Carolinas Sea Island slaves, unwinds as a flowing memory play told by two narrators but, toward the end of its 105 minutes, suddenly assumes the hard, inflexible contours of Greek tragedy. Alma (Deidrie N. Henry) is a dark-skinned Geechie girl helping raise chickens with her single, dirt-poor mother, Odelia, on the rural outskirts of town. Light-skinned Eugene (Chris Butler), the boy she meets in school as a 9-year-old, lives in a respectable home inside the city limits with his yellow mother, Thelma, and dark-complected father, Robert, whose anger over a lifetime of slights is murderously fueled by the tumblers of bourbon he consumes.

As they mature to adulthood, Alma and Eugene take turns telling how their characters separately came to befriend and eventually fall in love with each other, while also impersonating the couples family members and friends. Defeated and defeatist, Odelia constantly berates and belittles her love child for having nappy hair and big hips; Eugenes fellow yellow, Weiss, maliciously reviles their playgrounds darker children, including Eugenes friend, Alton. Like Alma, Eugene has an implacable enemy in a parent, and we soon sense Oedipal conflagration as Eugene recounts, with awe and fear, how his mill-hand father embodied that jet-black nigger stuff of John Henry legends and Robert Johnson songs.

A more palatable story about race in America  the kind were used to watching on TV or at the multiplex  would have featured perspiring villains and lofty goals. The first would have been white (Roberts foreman, maybe, or a local sheriff) while the-eyes-on-the-prize stuff might have involved a scholarship, a football team tryout or a winning recital. Yellowmans world, however, is a black planet separated from the rest of America by the unique history and dialect of the Gullahs  a pitiless world whose small pleasures invariably wilt. All light-skinned girls are bitches! Alma declares as a girl, and never really lets go of her anger toward butter-colored people, just as Robert tells his fair son that hes never loved him.

Orlandersmiths backwater may appear to be a brutal fantasy, yet this small, impoverished smudge of Carolina perfectly embraces the same scourges of exclusivity and resentment that ignite internecine conflicts elsewhere, from Yugoslavia to Ireland to Rwanda. The playwrights lesson is simply that skin and pronunciation are destiny, a moral she lays on lightly but unsparingly.

Its not difficult to understand this productions success. Director Shirley Jo Finney has mounted a nearly flawless show whose two actors completely evoke a forgotten South caressed by humid breezes and lorded over by the Georgia Pacific lumber company. Both Henry (who appeared in another production of the play at Berkeley Rep) and Butler are masters of finding the storys emotional recesses and of portraying characters who themselves are beguiling mimics  nowhere more so than when Alma and Eugene slide into Odelia and Roberts Caribbeanlike lilts. When I first saw this production, I was taken by Henrys effortless, Jekyll-Hyde transformations, in which her body seems to morph from nymph to monster as she switches back and forth from daughter, mother and runaway father. On second viewing, however, I was able to appreciate Butlers remarkable absorption of Eugene  a fragile and dreamy spirit encircled by the malignance of his father and Weiss, the two men in his life who epitomize the warring shades of black.

Scott Siedmans set, a mix of swamp-tree trunks, front-porch platform and expressionist backdrop, echoes the plays collision of romance and fate, while Kathi ODonohues lighting plot suggests a world where it is never clear if life is lived on the verge of dawn or night, peace or conflict. That question is answered by the plays end, when two people find they can escape myth, but never history.